this post was submitted on 10 Sep 2024
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What? They draw power, not energy?
Energy is just the product of power and time. And just like amperage, the power draw of a device varies.
And this should be obvious, but what makes more sense to an electronics engineer doesn't matter one bit to the end user. And the end user doesn't know anything about milli-amperes or volts (except maybe their wall outlet voltage).
Yes power is a rate. As you said energy is the time integral of power. So it's meaningless to state an "energy draw" without a duration implied or explicit. E.g. what does drawing 2kWh at idle even mean?
I agree about end user sentiment. I was trying to suggest as well. The only way to know which battery/phone is going to have a better battery life is to identify reviews with similar usage to your own or cross-compare metrics across devices you're familiar with. In general, phone A with a 4000mAh battery won't necessarily outlast phone B with a 4500mAh batt.
Well you don't say it draws 2 kWh at idle. You say it draws 2 kW at idle. While that is incredibly inefficient, it means that for every hour the device is idle, it draws 2 kWh of energy.
Oh yeah battery size isn't sufficient to fully gauge battery life. You need to know power draw to calculate that. And it's good to get battery life ratings from reviews. Great. It helps a lot.
But it doesn't mean we shouldn't get good, comparable physical specs.
Kinda like processors. Gigahertz and core counts are far from telling you everything, but it doesn't mean it should be abstracted into some weird unit.
Per the kW vs kWh, see top level reply.
Yeah a metric would be nice but it would need a standard test. That's why idle time and video playback time makes a good amount of sense. But it's not entirely clear how that would translate into usage for example in back country (where cell network drains power harder) or travel. So it's not perfect. But it is probably the best measure guven hardware and usage vatiation. In any case it's subject to marketing dudging the numbers in various ways.